Data from: Using genetic tools to estimate the prevalence of non-native red deer (Cervus elaphus) in a Western European population

Game species like the red deer have been subjected to anthropogenic impacts for centuries. Translocations are often carried out—sometimes illegally—not only for sporting purposes, but also to increase trophy quality, reduce inbreeding, or mitigate bottlenecks after excessive persecution. Apart from the blurring of large-scale genetic structure, translocations without adequate quarantine measure risk introducing pathogens into potentially immunologically naïve populations. It is therefore important to understand the frequency of clandestine translocations. Identification of non-autochthonous animals and their potential origin is often difficult and, in red deer, has been hampered by the lack of large-scale genotypic datasets for comparison. In the present study, we make use of a recently published European-wide microsatellite dataset to detect and quantify the presence of non-autochthonous red deer in a large population sample (n = 1,780) from Central Europe (Belgium). Using factorial correspondence analysis, assignment tests and Bayesian clustering algorithms we arrive at an estimate of 3.7% non-autochthonous animals (or their descendants). Some of these animals were assigned to a nearby French population and may have immigrated into Belgium naturally, but the large majority must have been introduced by humans. Our analysis pointed to the British Isles and Germany/Poland as the potential origin of many introduced deer, regions known to have been source populations for translocations in Europe and beyond. We found evidence for recreational hunters using carcasses from farmed deer to fulfill mandatory hunting quotas. Our study is the first to quantify the extent of human-mediated introductions in a European game species at such a large scale with large and representative sample sizes.

数个世纪以来，马鹿（red deer）这类猎用野生动物长期遭受人为活动的干扰。人为引种（translocation）行为频发，其中不乏非法操作；此类行为的目的不仅包括狩猎活动本身，还包括提升狩猎战利品品质、降低近交衰退风险，或是缓解因过度猎杀引发的种群瓶颈效应。除了会模糊种群的大规模遗传结构之外，未采取充分检疫措施的引种行为还可能将病原体引入原本对其缺乏免疫抵抗力的种群中。因此，摸清非法秘密引种行为的发生频率具有重要意义。甄别非本土个体及其潜在来源地往往难度极大，而在马鹿研究中，这一难题又因缺乏可用于比对的大规模基因型数据集而更为突出。本研究依托近期公开的欧洲全域微卫星（microsatellite）数据集，对采自中欧比利时的大型种群样本（n=1780）中的非本土马鹿个体及其占比进行检测与量化分析。通过因子对应分析、个体归属检验以及贝叶斯聚类算法，本研究估算出样本中非本土马鹿个体（及其后代）的占比为3.7%。其中部分个体被归属至邻近的法国种群，推测是自然迁入比利时，但绝大多数个体应为人为引种引入。分析结果显示，不列颠群岛以及德国/波兰是多数引种鹿群的潜在来源地——这两个区域已是学界公认的欧洲乃至全球范围内野生动物引种的源种群分布区。本研究还发现，存在休闲狩猎者利用养殖鹿的尸体来完成法定狩猎配额的情况。本研究是首次依托大规模且具有代表性的样本量，针对欧洲猎用野生动物的人为引种规模开展量化分析的研究。